SIST EN 10311:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Joints for the connection of steel tubes and fittings for the conveyance of water and other aqueous liquidsWHNRþLQAssemblages pour le raccordement de tubes en acier et raccords pour le transport d'eau et d'autres liquides aqueuxVerbindungen für Stahlrohre und Fittings für den Transport von Wasser und anderen wässrigen FlüssigkeitenTa slovenski standard je istoveten z:EN 10311:2005SIST EN 10311:2005en23.040.60Prirobnice, oglavki in spojni elementiFlanges, couplings and jointsICS:SLOVENSKI
STANDARDSIST EN 10311:200501-september-2005







EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 10311May 2005ICS 23.040.60English versionJoints for the connection of steel tubes and fittings for theconveyance of water and other aqueous liquidsAssemblages pour le raccordement de tubes en acier etraccords pour le transport d'eau at d'autres liquides aqueuxVerbindungen für Stahlrohre und Fittings für den Transportvon Wasser und anderen wässrigen FlüssigkeitenThis European Standard was approved by CEN on 25 March 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2005 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 10311:2005: E



EN 10311:2005 (E) 2 Contents Page Foreword.3 1 Scope.5 2 Normative references.5 3 Terms, definitions and symbols.6 4 Types of joint.7 5 Classification.12 6 Requirements.13 7 Testing.14 8 Evaluation of conformity.19 Annex ZA (informative)
Clauses of this European Standard addressing the provisions of the EU Construction Products Directive.22 Bibliography.27



EN 10311:2005 (E) 3 Foreword This document (EN 10311:2005) has been prepared by Technical Committee ECISS/TC 29 “Steel tubes and fittings for steel tubes”, the secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2005, and conflicting national standards shall be withdrawn at the latest by February 2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive 89/106/EEC. For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document. Compliance of a product with this document does not confer a presumption of fitness of the product for the transport of water intended for human consumption within the meaning of the Directive 89/106/EEC. However, until the operation of the envisaged European Acceptance Scheme for construction products in contact with water intended for human consumption and the revision of the present document, products complying with this document may be used for the transport of water intended for human consumption if they comply with the relevant national, regional or local regulatory provisions applicable in the place of use. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.



EN 10311:2005 (E) 4
Introduction This European Standard applies to joints for use with non-alloy steel tubular products for use with all types of aqueous liquids. In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this European Standard: a) This European Standard provides no information as to whether the product may be used without restriction in any of the Member States of the EU or EFTA; b) It should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations concerning the use and/or the characteristics of this product remain in force. Standards EN 1123-1 'Pipes and fittings of longitudinally welded hot-dip galvanized steel pipes with spigot and socket for waste water systems — Part 1: Requirements, testing, quality control' and EN 1123-2 'Pipes and fittings of longitudinally welded hot-dip galvanized steel pipes with spigot and socket for waste water system — Part 2: Dimensions' are also available for waste water systems which require galvanized tubes.



EN 10311:2005 (E) 5
1 Scope This European Standard specifies a range of jointing methods for connecting low alloy steel tubes and steel tubes and fittings for use with aqueous liquids. The following specific joint types are covered by this document: butt welded joints, welded spigot and socket (or sleeve joints), welding collars, flange joints, threaded joints, spigot and socket joints with seal and mechanical couplings. This European Standard specifies requirements for the strength and integrity of the joints and the testing of the joints. This European Standard does not specify the requirements for the tubes or the fittings. This European Standard is suitable for joints intended for the conveyance of water for human consumption, after an appropriate coating has been applied. This European Standard is not intended for use in heating networks where elevated temperature properties are required. Flexible joints which permit significant angular deflection, both during and after installation and which can accept slight offset of the centre line, are not covered by this European Standard. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 681-1, Elastomeric seals — Material requirements for pipe joint seals used in water and drainage applications — Part 1: Vulcanized rubber EN 1011-2, Welding — Recommendations for welding of metallic materials — Part 2: Arc welding of ferritic steels EN 1092-1, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN designated — Part 1: Steel flanges EN 1591-1, Flanges and their joints — Design rules for gasketed circular flange connections — Part 1: Calculation method EN 1759-1, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, Class designated — Part 1: Steel flanges, NPS 1/2 to 24 EN 10224, Non-alloy steel tubes and fittings for the conveyance of aqueous liquids including water for human consumption - Technical delivery conditions EN 10226-1, Pipe threads where pressure tight joints are made on the threads — Part 1: Taper external threads and parallel internal threads - Dimensions, tolerances and designation prEN 10226-2, Pipe threads where pressure tight joints are made on the threads — Part 2: Taper external threads and taper internal threads - Dimensions, tolerances and designation EN 10266:2003, Steel tubes, fittings and structural hollow sections — Symbols and definitions of terms for use in product standards



EN 10311:2005 (E) 6 EN 13479, Welding consumables – General product standard for filler metals and fluxes for fusion welding of metallic materials EN 13501-1, Fire classification of construction products and building elements. Part 1: Classification using test data from reaction to fire tests. EN ISO 6708, Pipework components — Definition and selection of DN (nominal size) (ISO 6708:1995) EN ISO 15607, Specification and qualificationl of welding procedures for metallic materials - General rules (ISO 15607:2003) 3 Terms, definitions and symbols For the purposes of this European Standard, the symbols given in EN 10266:2003 apply together with the following terms and definitions. 3.1 allowable maximum operating pressure (p) maximum pressure occurring from time to time, including surge, that a component is capable of withstanding in service [EN 805:2000] 3.2 collar short length of tube which is placed over the end of a tube or fitting and welded to it, to form a socket to receive the end of another tube or fitting 3.3 coupling mechanical joint for connecting identical or different pipe diameters and/or identical or different materials 3.4 fitting component, other than a pipe, which allows pipeline deviation, change of direction or bore of a tube. In addition, flanged-socket pieces, flanged-spigot pieces, collars and couplings are defined as fittings 3.5 joint connection between the ends of two components including the means of sealing [EN 805:2000] 3.6 adjustable joint joint which permits significant angular deflection at the time of installation but not thereafter [EN 805:2000] 3.7 rigid joint joint that does not permit significant angular deflection, either during or after installation [EN 805:2000] 3.8 nominal size (DN) see EN ISO 6708



EN 10311:2005 (E) 7 4 Types of joint 4.1 Butt welded joints Butt-welded joints shall be made between tubes or tubes and fittings with their ends prepared in accordance with EN 10224. The maximum gap between the ends of the tubes or the tubes and fittings when set up for welding shall be in accordance with EN 1011-2. 4.2 Welded spigot and socket (sleeve) joints 4.2.1 General Welded spigot and socket (sleeve) joints for welding shall comply with 4.2.2 or 4.2.3. The general form of the joints given in Figure 1 may differ in detail from one manufacturer to another, however the principal dimensions shown shall be measured, using appropriate equipment, and values shall be as stated, subject to the manufacturers stipulated tolerances. NOTE The dimensions of sleeve joints apply when they are shaped or made on tubes and/or fittings. On tubes and fittings of outside diameter smaller than 711 mm, the joint may be welded on the outside only. On tubes or fittings with outside diameter 711 mm and larger, welding may be either inside, or outside, or both inside and outside. Such joints have been designed to allow the same forces to be transmitted as if the welds were fillet welds of a size appropriate to the thickness of the materials being joined. 4.2.2 Spigot and socket (sleeve) joints (type 1) For type 1 joints (see Figure 1) the tubes or fittings shall be supplied with spigot end parallel and sleeve end either parallel or with the diameter tapered by approximately 0,8 mm on diameter per 25 mm length of sleeve. These latter joints are designed for taper sleeves, so that the depth of penetration of the spigot into the sleeve anywhere around the circumference shall be not less than 30 mm but shall also be sufficient, if applicable, to accommodate any holes made in the sleeve to permit testing of the joint. When used to accommodate small changes in pipeline direction, the spigot shall additionally penetrate the sleeve around the whole circumference to an average depth of not less than 40 mm. NOTE 1 At maximum penetration, the spigot can locate in the undimensioned transition area between the sleeve and the tube body. Care should be taken in expanding the tube end to prevent excessive weld gaps between the spigot and sleeve. The manufacturer or supplier shall obtain from the purchaser at the time of enquiry and order specific details of the end preparation necessary for tubes and fittings for use with these types of joint. NOTE 2 Assembly of sleeve joints on site in preparation for welding may require mechanical alignment aids e.g. props, jacks or wedges. 4.2.3 Spigot and socket (sleeve) joints (type 2) For type 2 joints (see Figure 1) the tubes or fittings shall be supplied with the spigot end and the sleeve end parallel. The collar forming the sleeve shall be fabricated with not more than one longitudinal weld and shall be welded externally and internally to the sleeve tube. To ensure an adequate space between the spigot end and the internal collar weld to effect the inside joint weld, if required, the minimum sleeve length shall be (150 + 2T) mm for D > 168,3 mm and (100+ 2T) mm for D ≤ 168,3 mm, where T is the wall thickness of the sleeve.



EN 10311:2005 (E) 8 75a a) Type 1 (parallel sleeve) 75a b) Type 1 (taper sleeve: taper approx. 0,8 mm on diameter
for each 25 mm on length of socket) NOTE All dimensions are in millimetres. 75 a
150 + 2Tb75 TTcc c) Type 2 (collar sleeve) NOTE All dimensions are in millimetres. Key
a For outside diameters ≤ 168,3 mm, the length indicated shall be ≤ 50 mm b For outside diameters ≤ 168,3 mm, the length indicated shall be 100 + 2T min c Workshop fabrication weld Figure 1 — Welded spigot and socket joints (these figures are idealised and do not take account of tolerances or site assembly conditions) 4.3 Welded collars An example of a welding collar is shown in Figure 2. Welding collars shall be at least equal in thickness to the adjoining components; the length of sleeve shall be not less than 250 mm.



EN 10311:2005 (E) 9 When positioned for welding the collar shall be a good fit on the outside diameter of the components to be joined. To ensure good welding conditions the gap between the collar and the tube shall be not greater than 3 mm. Welds employed shall be fillet welds of a size appropriate to the thickness of materials being joined and the forces to be transmitted, taking into account the guidelines in EN 1011-2. NOTE Dimensions are in millimetres. 7575123333 Key 1. Pipe 2. Collar 3. Weld Figure 2 — Welding collar 4.4 Flange joints Flange joints shall have flanges in accordance with EN 1092-1 or EN 1759-1, as appropriate to the design conditions (see Figure 3). The flange manufacturer or supplier shall obtain information at the time of enquiry and order specifying the type of flanges required.



EN 10311:2005 (E) 10
12 a) Plate flange 122 b) Loose flange 122 c) Welded neck flange Key 1
Seal 2
Weld Figure 3 — Flange joints 4.5 Threaded joints The threads of threaded joints shall be in accordance with EN 10226-1 or prEN 10226-2. The manufacturer or supplier of the threaded joints shall obtain information at the time of enquiry and order confirming the appropriate part of EN 10226 required. NOTE 1 Threaded joints are normally made between tubes in accordance with EN 10255 and fittings in accordance with EN 10241 (steel) and/or EN 10242 (malleable cast iron). NOTE 2 An appropriate sealing material should be applied to the threads before making the joint.



EN 10311:2005 (E) 11 4.6 Spigot and socket joints with seal A general form of a spigot and socket joint with seal is given in Figure 4.
As these types of joint can differ in detail from one manufacturer to another, the manufacturer shall define the principal dimensions at the time of enquiry and order. These dimensions shall be measured, using appropriate equipment, and values shall be as stated, subject to the manufacturers stipulated tolerances.
NOTE 1 The spigot and socket joint with seal shown in Figure 4 is a general form.
Details of other versions can be found in international and national publications.
NOTE 2
The connection is produced by inserting the spigot end into the socket end that contains a rubber seal. By inserting the spigot end into the socket, the rubber seal is deformed in an axial direction and seals the connection by the resilience present in the rubber seal. NOTE 3 The insertion depth of the spigot into the socket is critical to ensure good sealing.
Joint details can differ from one manufacturer to another and the insertion depth is normally specific to the particular make of joint used. NOTE 4 To absorb axial forces in the connection, special rubber rings can be required.
1 Key 1 Seal Figure 4 — Spigot and socket joints with seal (general form) 4.7 Seals Where joints utilise elastomeric seals (seals) these shall be in accordance with EN 681-1. 4.8 Couplings (slip-on type couplings) 4.8.1 Sleeve couplings A general form of sleeve coupling for use with plain end tube or fittings is given in Figure 5.
As the lengths S and L can vary from one manufacturer to another, the manufacturer shall define these principal dimensions at the time of enquiry and order.
These dimensions shall be measured, using appropriate equipment, and values shall be as states, subject to the manufacturer’s stipulated tolerances. NOTE 1 The sleeve length and tolerance at the end of the tube or fitting is specific to the particular make of coupling used.
NOTE 2 This type of coupling can be used for the connection of different diameters and/or different materials.



EN 10311:2005 (E) 12 SL
Figure 5 — Slip-on type couplings (general form) 4.8.2 Grooved and shoulder couplings A general form of a mechanical coupling for the axial alignment of tubes, or tubes and fittings, is given in Figure 6.
Each groove and coupling shall have a designated allowable operating pressure.
As these types of joint can differ in detail from one manufacturer to another, the manufacturer shall define the principal dimensions at the time of enquiry and order.
These dimensions shall be measured, using appropriate equipment, and values shall be as stated, subject to the manufacturers stipulated tolerances.
Figure 6 — Grooved and shouldered couplings (general form) 5 Classification 5.1 General Joints shall be classified as non-restrained (see 5.2) or restrained (see 5.3) and either rigid (see 5.4) or adjustable, (see 5.5).



EN 10311:2005 (E) 13 5.2 Non-restrained joints Non-restrained joints shall have adequate axial withdrawal to accommodate any axial spigot movement induced by temperature fluctuations and the Poisson contraction of the tube or tube and fitting under internal pressure in addition to the specified angular deflection. NOTE Spigot and socket joints with seal and some mechanical joints e.g. slip-on couplings are non-restrained joints. 5.3 Restrained joints Restrained joints shall withstand the end-thrust due to internal pressure and, where applicable, due to temperature fluctuation and the Poisson contraction of the tube or tube and fitting under internal pressure. NOTE Butt-welded joints, welded spigot and socket (or sleeve) joints, welding collars, flanged joints, threaded joints and some mechanical couplings are restrained joints. 5.4 Rigid joints Rigid joints shall maintain the axial alignment of tubes or tubes and fittings to within 2°. NOTE Butt-welded joints, spigot and socket (or sleeve) joints (after welding), welding collars, flanged joints, threaded joints and some mechanical couplings are rigid joints. 5.5 Adjustable joints Adjustable joints shall accommodate angular displacement of tubes or tube and fitting of not less than: 3 ° 30’ for D ≤ 300 2 ° 30’ for D 300 mm to 700 mm 1 ° 30’ for D > 700 mm NOTE Welded spigot and socket (or sleeve) joints with taper sleeves before welding, spigot and socket joints with seal and some mechanical couplings are adjustable joints. 6 Requirements 6.1 General Joints shall exhibit no visible leakage or ingress, as appropriate, of aqueous liquid when subjected to the following type tests by the manufacturer:  Test 1: positive internal hydrostatic pressure in accordance with 7.3.2; the type test pressure shall be 1,5 p + 5 bar1).  Test 2: negative internal pressure of 0,8 bar below atmospheric pressure (approximately 0,1 bar1) absolute pressure), in accordance with 7.3.3.  Test 3: positive external hydrostatic pressure of 2 bar1), in accordance with 7.3.4 when intended for use at depths greater than 5 m below water level.
1) 1 bar = 100 kN/m2 = 100 kPa.



EN 10311:2005 (E) 14  Test 4: under test condition 1 (see 7.2.1), dynamic internal hydraulic pressure in accordance with 7.3.5; the test shall comprise at least 24 000 pressure cycles between 0,5 p and p. This test applies to spigot and socket joints with seal (see 4.6).  Where p is the allowable maximum operating pressure of the joint declared by the manufacturer. Where it can be shown by either physical test results (see 8.1), calculation or compliance with tabulated values that joint designs that have already been in service for a minimum of 10 years prior to the first publication of this document can meet the necessary essential characteristics, then Test 4 shall be deemed not to be necessary. NOTE These joints are generally tested after on-site installation. All other types of joint shall be leak-tight when tested in accordance with Clause 7. 6.2 Reaction to fire Uncoated ferrous product material is class A1.2).
Products supplied coated or lined, when the coating contains more than 1,0 % by weight or volume (whichever is the lower) of homogeneously distributed organic material shall be tested and classified according to EN 13501-1 NOTE Seals are encased in steel or cast iron and their reaction to fire is therefore not relevant. 6.3 Dangerous substances Materials used in the production of joints shall not release any dangerous substances in excess of the maximum permitted levels specified in a relevant European Standard for the material or permitted in the national regulations of the member state of destination 7 Testing 7.1 General Type testing shall be carried out under the most adverse conditions of tolerance, angularity of tubes and or fittings, and joint movement relevant to the design of joint. Type testing shall be carried out using one representative tube (or fitting) size in each of the groups given in Table 1: Table 1 — Preferred outside diameter of tubular products for type testing Dimensions in millimetres
Outside diameter groups
≤ 323,9 >323,9 ≤ 610 >610 ≤ 1016 >1016 D, preferred, in each group 219,1 406,4 813 1626
2) In accordance with Commission Decision 96/603/EEC of 4th October 1996 (as amended by Commission Decision 2000/605/EC) the ferrous product material is class A1 and therefore does not require to be tested for reaction to fire.



EN 10311:2005 (E) 15 If a group covers products of different designs and/or manufactured by a different process, the group shall be sub-divided into families representative of the different types and designs. NOTE If, for a manufacturer a group contains only one outside diameter (D) this may be considered as part of the adjacent group provided that it is of identical design and manufactured by the same process. The thinnest wall thickness tubular product shall be tested in each size range. 7.2 Test conditions 7.2.1 Spigot and socket joints Spigot and socket joints shall be tested in the conditions indicated below: a) Joint of maximum annulus (see 7.2.2) aligned, withdrawn to the allowable value declared by the manufacturer, and subject to shear (see 7.2.3). b) Joint of maximum annulus (see 7.2.2) deflected to the allowable value declared by the manufacturer. 7.2.2 Annulus Spigot and socket joints shall be type tested at the extremes of manufacturing tolerance such that the annular gap between the sealing surfaces of the socket and of the spigot is equal to the maximum design value plus 0 %, minus 2 %. It is permissible to machine socket internal surfaces to achieve the required annulus for the type-test even though the resultant diameter can be slightly outside the normal manufacturing tolerance. 7.2.3 Shear All joints shall be type-tested with a resultant shear force across the joints of not less than 50 times D in Newtons, taking into account the weight of the tube or fitting, its contents and the geometry of the test assembly (see Figure 7). 7.3 Type tests 7.3.1 General The type tests to demonstrate compliance with the requirements specified in Clause 6 are given in 7.3.2, 7.3.3, 7.3.4 and 7.3.5. 7.3.2 Leak tightness of joints to positive internal pressure 7.3.2.1 General The test shall be carried out on an assembled joint comprising two tubes and/or fittings with sections each at least 1 m long (see Figure 7). The test apparatus shall be capable of providing suitable end and lateral restraints whether the joint is in the aligned position, or deflected, or subjected to a shear load. It shall be equipped with a pressure gauge with an accuracy of ± 3 %. The vertical force W shall be applied to the spigot end by means of a V shaped block with an angle of 120 ° located at approximately 0,5 times D in millimetres or 200 mm from the socket face whichever is the largest; the socket shall bear on a flat support. The vertical force W shall be such that the resultant shear force, F, across the joint is equal to the specified value, taking into account the mass M of the pipe and its contents and the geometry of the test assembly: acbcMcxFW-)-(-
=



EN 10311:2005 (E) 16 where a, b and c are as shown in Figure 7. wfwcbaw Figure 7 — Test assembly for test for leak tightness of joints subjected to positive internal pressure 7.3.2.2 Procedure Fill the test assembly with water. Vent the test assembly of air. Raise the pressure steadily until it reaches the test pressure given in Clause 6. Ensure the rate of pressure increase does not exceed 1 bar3) per s. Keep the test pressure constant within ± 0,5 bar3) for at least 2 h. During this time, inspect the joint thoroughly every 15 min. Take all necessary safety precautions during the pressure test. For a restrained joint, the test assembly, the test apparatus and the test procedure are identical except that there is no end restraint, so that the restrained joint under test takes the axial thrust. Possible axial movement of the spigot is measured every 15 min. 7.3.3 Leak tightness of joint to negative internal pressure 7.3.3.1 General The test assembly and test apparatus shall be as given in 7.3.2 with the tube and/or fittings sections axially restrained to prevent them moving towards each other, or as given in 7.3.4. The test assembly shall be empty of water. 7.3.3.2 Procedure Evacuate the test assembly to a negative internal pressure of 0,8 bar3) (see 6.3.4) and isolate from the vacuum pump. Leave the test assembly under vacuum for 2 h. At the end of 2 h check the vacuum has not changed by more than 0,09 bar3). Begin the test at a temperature between 15 °C and 25 °C. Keep the temperature within ± 2 °C of the chosen test temperature, for the duration of the test. NOTE For a restrained joint, the test assembly, the test apparatus and the test procedure are identical.
3) 1 bar = 100 kN/m2 = 100 kPa



EN 10311:2005 (E) 17 7.3.4 Leak tightness of joints to positive external pressure 7.3.4.1 General This test applies to spigot and socket joints with seal (see 4.7). For couplings, the test shall be indicated at the time of enquiry and order. The test assembly shall comprise two joints made with two tube and/or fittings sockets welded together and one double-spigot piece (see Figure 8). NOTE The test assembly creates an annular chamber that allows testing of one joint under internal pressure and one joint under external pressure. M/2M/2M/2M/2M/2M/2 Figure 8 — Test assembly for test for leak tightness of joints to positive external pressure



EN 10311:2005 (E) 18 7.3.4.2 Procedure Fill the test assembly with water and vent to remove air. Raise the pressure steadily until it reaches 2,0 bar4). Keep the test pressure constant within ± 0,1 bar4) for a minimum of 2 h. During this time, inspect the joint thoroughly every 15 minutes. NOTE For a restrained joint, the test assembly, the apparatus and the test procedure are identical. Subject the test assembly to a vertical force W equal to the shear force, F defined in 7.3.2.1. Apply one half of the load to the spigot end on each s
...